Fluid actuated starter assembly

ABSTRACT

AN IMPROVEMENT IN A STARTER ASSEMBLY OF THE TYPE INCLUDING A FLUID MOTOR, A SHAFT DRIVEN THEREBY, AND A PINION GEAR AXIALLY MOVEABLE ALONG THE SHAFT FOR ENGAGEMENT WITH AN ENGINE GEAR. A FLUID INLET IS PROVIDED IN THE HOUSING AND A PORT CONNECTS THE FLUID INLET WITH THE FLUID MOTOR, AND A PISTON IS PROVIDED IN THE INLET FOR OPENING AND CLOSING THE PORT. MECHANICAL MEANS ARE PROVIDED INTERCONNECTING THE PISTON WITH THE PINION GEAR TO MOVE THE PINION GEAR AXIALLY ALONG THE SHAFT IN RESPONSE TO FLUID PRESSURE. THE PISTON IS SO POSITIONED THAT IT IS MOVEABLE TO A POSITION WHEREIN THE PORT IS SLIGHTLY EXPOSED WHEN THE PINION GEAR IS ABOUT TO ENGAGE THE ENGINE GEAR TO PERMIT A PORTION OF THE PRESSURIZED FLUID TO ENTER THE FLUID MOTOR AND CAUSE ROTATION OF THE SHAFT.

Nov. 2, 1971 Filed June 11, 1970 L- E. SMITH EIAL FLUID ACTUATED STARTER ASSEMBLY 3 Sheets-Sheet 1 FIG INVENTOR S LESTER E. SMITH DONALD E. BENDER BY fi/ SWI/QM ATTORNEY Nov. 2, 1971 L. E. SMITH ETAL 3,616,785

FLUID ACTUA'I'ED STARTER ASSEMBLY Filed June 11, 1970 3 Sheets-Sheet 2 k \fig FIG-2 INVENTORS LESTH? E. SM/TH DONAL!) EBENDER BY VMIMZLQ ATTORNEY 1971 L. E. SMITH ETAL 3,616,785

FLUID ACTUATED STARTER ASSEMBLY Filed June 11, 1970 3 Shouts-Shoot 8 FIG'4 INVENTORS 55 LESTER E. SMITH DONALD E. BENDER [1/6 -5 BY film/Xi ATTORNEY United States Patent G US. Cl. 123-179 F 8 Claims ABSTRACT OF THE DISCLOSURE An improvement in a starter assembly of the type including a fluid motor, a shaft driven thereby, and a pinion gear axially moveable along the shaft for engagement with an engine gear. A fluid inlet is provided in the housing and a port connects the fluid inlet with the fluid motor, and a piston is provided in the inlet for opening and closing the port. Mechanical means are provided interconnecting the piston with the pinion gear to move the pinion gear axially along the shaft in response to fluid pressure. The piston is so positioned that it is moveable to a position wherein the port is slightly exposed when the pinion gear is about to engage the engine gear to permit a portion of the pressurized fluid to enter the fluid motor and cause rotation of the shaft.

This invention relates generally to fluid actuated starter assemblies for compression ignition or turbine engines and in particular to a fluid actuated starter assembly which includes means for providing a drive connection between the drive assembly of the starting motor and the flywheel of the engine to be started.

In order to start a compression ignition engine, its crank shaft must be rotated by some outside means so that the air in the cylinder is compressed to such a pressure and temperature that, when the fuel is injected into the cylinder, it will ignite and produce 'a powerful stroke. The various outside means for rotating the engine at the proper speed include auxiliary electric motors, auxiliary gasoline engines, and fluid actuated motors. The present invention is concerned with a fluid actuated motor.

In known fluid actuated starting systems, various methods have been proposed to engage the drive pinion of the starting assembly with the flywheel ring gear of the engine. One such system utilizes control air bled from a source of fluid pressure through a starting valve to a piston in the drive assembly. The pressure of the fluid serves to move the piston which in turn moves the drive gear into engagement. After the drive pinion is in proper engagement, the piston has been moved to a point wherein an outlet is uncovered to permit the control fluid to flow to a motor inlet valve and open that valve to permit fluid from the source of fluid pressure to flow to the starting motor.

Another system utilizes control air to move a piston in the drive assembly which in turn moves the pinion of the drive assembly into proper engagement with the ring gear of the flywheel. In this particular system, a bleed off for the control air to the motor inlet valve is provided so that when proper engagement is achieved, sufficient pressure is built up to actuate the motor inlet valve to permit air from its storage container to flow to the starting motor.

In both of the above systems, special tubing is required for the control fluid. In addition, there is a possibility that the engine ring gear may be damaged due to the fact that the starter pinion may not be properly aligned with the engine ring gear as the pinion is moved into the proper position.

Accordingly, one of the objects of the present inven- 3,616,785 Patented Nov. 2, 1971 "ice tion is the provision of an improved engaging mechanism for the drive pinion of a starter motor.

Another object of the present invention is the provision of a starting device incorporating means for rotating the drive pinion in the event there is improper alignment with the engine ring gear.

Yet another object of this invention is to provide a simple and relatively inexpensive starting system.

These and other objects of the present invention will become more apparent by reference to the following description of a preferred embodiment of this invention and to the accompanying drawings in which:

FIG. 1 is a side sectional view of the preferred embodiment of the starter assembly;

FIG. 2 is a side view, partially in section, of the piston, cam, drive block and housing which serve to provide motion to the drive pinion for engagement with the engine ring gear;

FIG. 3 is a transverse sectional view taken along the lines 3--3 of FIG. 1;

FIG. 4 is a side sectional view of the drive assembly and engagement mechanism showing the various components in their respective position at the time the pinion gear is about to engage the ring gear of the engine;

FIG. 5 is a view similar to FIG. 4, but showing the components in their respective positions when the pinion gear fully engages the engine ring gear; and

FIG. 6 is a schematic diagram of the starter assembly as incorporated into a starting system.

Referring more particularly to the drawings, the starter assembly 2 of the present invention includes a fluid motor 4, a drive assembly 6 and pinion engaging means 8. The fluid motor 4 of the preferred embodiment is a vane motor 10 of the type including an outer housing 12, a rotor casing 14 having a cylindrical inner surface 16 and a rotor 18 mounted eccentrically with respect to the axis of the cylindrical inner surface 16 of the casing 14. The fluid inlet 20 extends from a cylindrical manifold 22 in an intermediate housing 23 to passages 24 in the rotor casing 14 which in turn communicate with the interior of the rotor casing 14 defined by the cylindrical inner surface 16.

The rotor 18 is provided with a series of circumferentially spaced, longitudinally extending slots 26 in which are mounted vane members 28 which are movable radially inwardly and outwardly in their respective slots. Each of the vane members 28 are biased outwardly by means of a spring member 30 mounted between the bottom of the slots 26 and the vane members 28.

The rotor 18 of the vane motor 10 is attached to the drive assembly 6 by means of a pinion gear 32 drivingly attached to the rotor 18 which in turn engages a drive gear 34 on the drive shaft 36 of the drive assembly 6.

The drive assembly 6 is contained within a suitable housing 38 and includes an overrunning clutch assembly 40 in splined engagement with the drive shaft 36 but whereby the clutch assembly 40 is capable of relative axial movement with respect to the drive shaft 36. Any conventional clutch assembly may be used and as such assembly is well known and as the details thereof do not form a part of this invention, the clutch assembly 40 has only been shown diagrammatically in the drawings. A pinion gear 42 is operably connected to the clutch assembly 40 so that it will move axially on the drive shaft 36 with it and be driven thereby when the drive shaft 36 drives the clutch assembly 4-0. As is well known, the clutch assembly 40 permits the pinion gear 42 to turn relative to the drive shaft 36 after the engine speeds up to prevent damage to the starter assembly.

The inlet manifold 22 extends in a direction generally perpendicular to the axis of the drive shaft 36. A piston member 44 is mounted for reciprocal movement in the manifold 22 and has a rod 46 connected thereto and extending in a direction toward the drive shaft 36.

The rod member is guided by a bushing 48 mounted in the intermediate housing 23. A cam member 50 is attached to the end of the rod 46 opposite the piston member 44. The cam member 50 is generally in the form of an inverted U with the base thereof 52 having a threaded bore '54 into which the tip of the rod member 44 is threaded. The two legs 56 and 58 of the cam member 46 extend on either side of the drive shaft 36 with the surfaces of the legs facing the pinion gear 42 being tapered to form cam surfaces 60 and 62. As can be seen in FIG. 1, the surfaces taper in a direction away from the pinion gear 42 and downwardly from the piston member 44. A return Spring 64 is provided between the base of the piston member 44' and the bottom of the manifold 22 to return the piston member 44, rod 46 and cam members 50 to their rest position shown in FIG. 1.

A drive block 66 is mounted on the drive shaft 36 in a manner whereby the drive shaft 36 may rotate relative thereto. The drive block 66 includes cam follower surfaces 68 and 70 spaced on opposite sides of the drive shaft 36 which are engaged by the tapered surfaces 60 and 62 of the cam member 50. The end of the drive block 66 facing the pinion gear 42 is provided with an L-shaped flange 72 which extends generally outwardly and toward the-pinion gear 42. The clutch assembly 40 includes two spaced washer members 74 and 76 which are attached to an internally splined sleeve 78. The splines on the sleeve 78 cooperate with the splines on the drive shaft to provide a rotary drive connection therebetween while permitting relative axial movement. An L-shaped collar member 80 surrounds the clutch assembly 40 between the two spaced washer members 74 and 76. The collar member 40 is attached to the drive block 66 by means of a plurality of screw members 82. Enough clearance is provided between the collar member 80 and the clutch assembly 40 to per- I mit the clutch assembly 40 to rotate relative thereto. A

return spring 84 is positioned between a shoulder 86 in the housing 38 of the drive assembly 6 and the collar member 80- to bias the drive block 66 to its rest position in a direction away from the ring gear of the engine (shown schematically as gear 88).

If desired, a bellows 90 may be positioned between a juncture 92 in the housing assembly and the juncture between the flange 72 of the drive block 66 and the collar 86 to prevent dirt and other foreign matter which may escape past the piston member 44 from coming in contact with the clutch assembly 40.

It will be noted that when the starter assembly 2 is in its rest position as shown in FIG. 1, the piston member 44 'blocks the fluid inlet 20 from the inlet side of the manifold 22. When the starter assembly 2 is mounted in the system as shown in FIG. 6, the pinion gear 42 is spaced a predetermined distance from the ring gear 88 of the engine. The manifold 22 is connected to a source of fluid pressure such as a tank of compresed air 94 or a breech mechanism 96 which is capable of firing a propellant charge which may be in the form of a cartridge. The system may also include a valve 98 connected to the outlet of the compressed air tank 94 which serves as the control valve for an air start. The valve 98 may be actuated pneumatically, manually, or electrically. In the case shown, a switch 100 is connected by suitable wiring to the valve 98 and also to a source of electrical power such as a battery (not shown) whereby upon activation of the switch 100, the valve 98 will open.

The breech mechanism 96 is connected to a manifold 102 by a hot gas conduit 104 which joins the main air conduit 106 at a T-shaped connection 108 adjacent the starter assembly 2. The main air conduit 106 is provided with a check valve 110 adjacent the connection 108 to prevent gas from the burning of the propellant charge from flowing to valve 98.

When it is desired to start the engine, the operator actuates either the breech mechanism 96 for a cartridge start or the valve 98 for an air start to permit fluid to flow from its source into the manifold 22. The piston member 44 will then move downwardly within the manifold 22 as viewed in FIG. 1 whereupon the cam surfaces 60 and 62 of cam member '50 will act upon the cam follower surfaces 68 and of the drive block 66 causing the drive block 66 to move to the left. The drive block 66 pushes against the washer member 74 and forces clutch assembly 40 and pinion gear 42 toward the ring gear of the engine. At the point where the piston member 44 has begun to uncover the inlet 20, the pinion gear 42 will be in a position wherein it just about abuts the ring gear 88. If, at this point, the teeth of the pinion gear 42 and ring gear 80 do not mesh, the fluid will flow through passage 20 into the fluid motor 4 and cause the rotation thereof. The rotation of the fluid motor 4 will be transmitted to the pinion gear 42 causing rotation thereof until the teeth are in alignment with the teeth of the ring gear 88. As the fluid is still acting upon the piston member 44, the piston member 44 will move downwardly until the entire inlet 20 is exposed to the manifold 22 and the pinion gear has been moved into full engagement with the ring gear 70 as shown in FIG. 5. The rotation of the rotor 18 of the fluid motor 4 will be transmitted through pinion gear 42 to the engine ring gear 88 to provide initial cranking of the engine. When the pressure is relieved, the piston member 44 will be forced upwardly into its normal position as shown in FIG. 1 by return spring 64. The clutch assembly '40, pinion gear 42, and drive block 66, and collar member 80 will be returned to their original positions by spring 84 which acts upon the collar member 80 which transmits the return force to the washer member 74.

What is claimed is:

1. In a starter assembly of the type including a fluid motor, a shaft driven thereby, a pinion gear axially movable along the shaft for engagement with an engine gear, the improvement comprising a housing, a fluid inlet in said housing, a port connecting said fluid inlet with said fluid motor, first means in said inlet for opening and closing said port to said inlet, second means interconnecting said first means with said pinion gear for moving said pinion gear axially along said shaft in response to fluid pressure entering said inlet, said first means being movable to a position wherein the port is slightly exposed when said pinion gear is about to engage said engine gear and moveable to a position wherein said port is completely exposed when said pinion gear is in full engagement with said engine gear.

2. In a starter assembly of the type including a fluid motor, a shaft driven thereby, a pinion gear axially moveable along said shaft for engagement with an engine gear, the improvement comprising a housing, a fluid inlet in said housing, a port connecting said fluid inlet with said fluid motor, a piston mounted in said inlet for movement in response to fluid pressure between a first position wherein said port is closed with respect to said inlet to a second position wherein said port is wholly exposed to said inlet, means interconnecting said piston with said pinion gear on said shaft in response to movement of said piston with said piston exposing a portion of said port to said inlet prior to the engagement of said engine gear by said pinion gear and exposing all of said port to said inlet upon full engagement of said pinion gear with said engine gear.

3. The starter assembly of claim 2 further including means for returning said piston and said pinion gear to their first positions.

4. The starter assembly of claim 2 wherein said means interconnecting said piston and said pinion gear includes a drive block mounted on said shaft for axial movement with respect thereto, said drive block being operably 5 connected to said pinion gear to impart axial movement thereto and having a cam follower surface thereon, and a rod member extending from said piston in a direction transverse to the axis of said shaft and terminating in .1 cam member having cam surface means in engagement with the cam follower surface of said drive block.

5. The starter assembly of claim 4 wherein the axis of said piston is perpendicular to the axis of said shaft.

6. The starter assembly of claim 4 including a collar exposed about said shaft and attached to said drive block and an overrunning clutch assembly contained between said collar and said drive block for axial movement therewith along the shaft and for relative rotational movement therewith.

7. The starter assembly of claim 6 including a shoulder in said housing and spring means extending between said shoulder and said collar for urging said pinion gear out of engagement with said engine gear.

8. The starter assembly of claim 7 including a spring means for returning said piston to its first position.

References Cited UNITED STATES PATENTS 2,498,697 2/1950 M-olyneux et al. 123-179 F 2,506,663 5/1950 De Guerin 123--179 F 2,710,606 6/1955 Jenny 123l79 F 2,711,724 6/1955 Jenny 123179 F 2,802,452 8/1957 Hogeman 123-179 F X 3,051,136 8/1962 Muehlhausen 123-179 F X 3,182,650 5/1965 Heckt 123-l79 F 3,413,860 12/1968 Heckt 74-6 AL L. SMITH, Primary Examiner US. Cl. X.R. 746; 418181 

